Chapter 9, Problem 87GP

Predict/Calculate Weighing a Block on an Incline A wedge of mass m, is firmly attached to the top of a scale as shown in Figure 9-47. The inclined surface of the wedge makes an angle θ with the horizontal Now a block of mass m₂ is placed on the inclined surface of the wedge and allowed to accelerate without friction down the slope (a) Show that the reading on the scale while the block slides is

(m₁ + i₂ cos²θ)g

(b) Explain why the reading on the scale is less than (m₁ + m₁)g. (c) Show that the expression in part (a) gives the expected results for θ = 0 and θ = 90°.

Figure 9-47

Problem 87